Caster.



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1,033,264. mem .my 23, 1912.

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0 A Attorneys ABRAHAM B. OPPY, OF KANSAS CITY, MISSOURI.

cAsTER.

Specication of Letters Patent.

Application led September 2, 41911.

Patented J'ulyza, 1912. serial No. 647,434.

To all whom t may concern.' I

Be it known-that I, ABRAHAM B. OPPY,V a citizen of the United States,residing at Kansas City, inthe c'ounty ofJackson and State of Missouri,have invented a new and useful Caster, of which the following is aspecication. .A

This invention relates to builders hardware, and more especially tocasters; and the object of the same is to produce a ball caster whereinthe ball bears against anti-friction devices -Which are in turnremovably held in place in such' manner asto reduce the friction to aminimum. This end I accomplish by the construction hereinafter morefully described and claimed, and as shown in the drawings wherein-Figure 1 is a" side elevation and Fig. 2 a central` vertical section ofone form of this improved caster. Figs. 3 and 4 are horizontal sectionson the lines 3 3 and lr-4 of Fig. 2. Fig. 5 is a central verticalYsection through a slightly modified type of this invention, showing thestem and upper portion thereof in side elevation.

The stem S of this caster may be variously formed. In Fig. 2 it is shownas a plug 5 adapted to be driven into the lower end of the leg of apiece of furniture in a manner well understood, and a plate 6A surroundssaid plug and has holes 7 for the insertion of screws or other similardevices by means of which the plate can be secured upon the leg. In Fig.5 the stem is shown as a screw 8, and by preference the same plate 6 isemployed although here it need not have the holes 7 for the screws asthe threads of the main screw 8 will perform the service of holding thestem in place. It will be understood that the stem might be made in avariety of forms with- .-out in anywise affecting the principle of myinvention, which I will now describe.

The ball B of this Aball caster is revolubly mounted within a casing Cas usual in casters of this type, excepting that the means I provide fortaking the thrust or load from the superimposed piece of furniture andapplying it to the ball is such asto bring the latter into as few pointsofcontact within theA surrounding members aspossible, and consequentlythe construction of the casing will be modiiied to correspond.

The caster ball B herein is'the one whichv rests upon the floor, andl isof some-considerable size and preferably made of4 har- .smaller ball'10,

dened steel. Directly above and -in axial alinement with it is disposedva second and preferably also of hardened steel, which guish throughoutthis specification by the. term thrust ball because it receives thethrust or load. This ball 10 is mounted within a square chamber 11formed within the casing C, the lower end of this chamber .opening intoor communicating with the somewhat larger chamber 21 which contains theball B, and the upper end 12 of said .chamber 11 being fiat except for acavity 13 in which the upper extremity of this thrust ball 10 rests asbest seen in Fig. 2. The latter thus receives the direct thrust of theload, as the weight'of the piece of furniture is communicated downwardthrough the stem S, cavity 13, thrust ball 10, and by the latter to thecaster ball B through the single point 15 of contact between them.

The ychamber 21 referred `to isherein shown as having conical walls 22,although that is a matterof preference so long as they do not come inContact with the caster ball B, and therefore as far as this descriptionhas proceeded said ball touches nothing but the thrust ball and touchesthat only at the point l5. p

Below the chamber 21 the casing C is formed with an internal annularrecess v31 having a straight upright outer wall 32 in which is cut asemi-circular groove 33, it being understood that this recess, its wall,and the groove therein extend around the caster bali.. At its upperportion said recess communicates with the chamber 21, and at its lowerportion'said recess is open downward as at 34: in what Disposed withinthe recess ,is an annular collar 35 whose body is rectangular in crosssection as seen in Fig. 2, and it is my intention to cut this collarquite accurately so that normally- -it shall no-t Contact on its outerface with the outer wall 32 of the recess, .on its inner face with thecaster ball B, or on its upper and lower edges with anything; andthrough this collar are formed about four truly radial and cylindricalholes 36 as best seen in Fig. 3, their diameter correspondingaccuratelyl with lthat of fo-ur it may be well to distin-l completelyV.might be called the mouth of the casing.

anti-friction balls 37 which are also made of hardened steel. Theselatter are' of a diameter to'it closely and to run nicely within thesemi-circulargroove 33 above described,

and saidgroove is so-disposed and said balls are ofsnch sitze that whenin place they touch the caster ball at four points only as indicated bythe numeral 39 in Fig. 3; It follows that as roceeded, the caster balltherefore touches the thrust ball at one point and the antifrictionballs at four other points, so that it has contact at-five points inall. It the collar be formed as neatly as it is my intention, its weightwill be supported by the anti-friction balls 37 and it will constitute aspacer for holding them equi-distant from each other as they travelaround within the groove 33 and while it is true that this collar maytouch the caster ball or the wall 32, it can never touch either with anyhigh degree of friction because its width radial of the device is lessthan half the diameter .of the anti-friction balls 37 and they alonetake the lateral thrust from the caster ball B.

For holding the parts in place I provide a cup 40 having a cylindricalbody which surrounds the lower end of the casing C, and a flange orbottom 41 which is flat so as to extend across the 'lower end of saidcasing and across the lower edge of the col-V lar 35 and is pierced withan opening 44 at its center, which opening is smaller than the mouth oropen lower end 34 of the chamber 21 and is also smaller than anydiameter of the caster ball B. The casing is by prefer'- ence providedwith a flatsurrounding shoulder 45, and 46 designates lugs or earsformed upon the upper edge of the cup 40 and adapted to be bent overonto said shoulder 45 to hold the cup in place as best seen in Fig. 1.This cup pliable material and will be suitably ornamented. I consider itessential that the opening 44 through the base or flange 41 of this cupshall be smaller than the diame# ter of the caster -ball B so as toprevent the latter from dropping out of place, and also smaller than thelargest diameter of the collar 35 so as to prevent that also fromdropping out of place, but it will be understood that its ordinaryfunction is merely to support said collar and not the caster ball B asthe latter is borne upwardly in the constant use of the caster as awhole.

The manner of assembling the parts of this improved device is asfollows: The caster (or the piece of furniture with the caster on it)being inverted, the thrust ball l() is first dropped into the chamber11,

then the collar 35 is dropped into the annular recess 31, then thefouranti-friction balls 37 are inserted in the holes 38 in the collarand borne radially outward until they enter the groove 33 in the casingC, then the caster ball is dropped into place and when in place itprevents any of the anti-friction balls from getting out of place,andfinally the cup 40 is applied and its far as this description hasv istherefore by preference made of.

maaeea luo's 46 bent over onto the shoulder 45 to hozld it in position.'As seen in the sectional view in Fig. 2, this cup serves both to holdthe collar 35 and anti-friction balls 3T in place and also to preventthe caster ball B from falling out when the furniture is lifted off thefloor. I

The modification illustrated in Fig. 5 is so slight that it hardly needsfurther explanation.v Herein the upper chamber 11 is practically thesame and has the cavity 13 at its apex, the caster ball B is again thesame but is located within a chamber 21 whose wall 220 is rounded ratherthan being truly conical as shown in Fig. 2; the collar and theanti-friction balls are the same; and the cup instead of having anupright side wall with a fiat flange, is slightly rounded as at 400 atits lower corner, although here again it has the lugs 46 to hold it inplace upon the casing C. i

W hat is claimed is:

1. A caster including a casing having an interior annular groove, a ballloosely mounted in the casing and projecting therebelow, means forretaining the ball within the casing, anti-friction balls mounted totravel within the groove and contacting with the first named ball tospace it from the casing, and means carried by and movable with thespacing balls for holding themout of contact with each other, said moansbeing supported out of contact with the casin g and with the first namedball.

2. In a ball caster, the combination with a casing having aninternal'chamber for the caster ball, a smaller chamber above and in theaxis of said caster-ball chamber and communicating therewith, a cavityat the top of said chamber, and an annular recess below said caster-ballchamber and opened downward through the mouth of the latter; of thecaster-ball located within its chamber, a thrust ball located in saidsmaller chamber and resting in the cavity thereof, a series ofanti-friction balls, a spa-cer for them,these balls and their spacertraveling in said recess, a cup having a flange extend` ing across thelower end of said casing beneath said spacer and whose opening issmaller than any diameter of said caster ball, and means for holding thecup removably upon the casing.

3. In a ball caster, the casing having a chamber ball, a smaller chamberabove eating with it, an annular recess beneath and communicating withthe caster-ball chamber and having an upright outer wall with asemi-circular groove in it, the lower end of this recess opening at thebottom of the casing, and a shoulder' surrounding the latter; of thecaster ball located in its chamber,a thrust ball above and in axialalinement with it, a series of anti-friction balls diameter of'saidcaster ball, and whose upper edge has lugs bent over upon sald shoulder.Y

In testimony at I claim the foregoing asl 1'5 my own, I have heretoaixed my slgnature in the presence of two witnesses.

Y l ABRAHAM B. OPPY.

' Witnesses: v

RUDOLF LETER,

O'rIS E. CnoNx.

